HUMAN LONGEVITY. 129 



moral causes in their influence on the animal economy of 

 man. Of hereditary temperament we have already spoken. 

 But apart from this, the whole of life teems with personal 

 incidents which must needs affect, more or less, its duration. 

 Every particular variation of health, however produced, has 

 some definite relation, perceptible, or not, to this result. The 

 physical conditions and habits of the individual, whether 

 those of luxurious sensuality or of meagre poverty, are in 

 constant action here ; and associated with these the various 

 occupations, whether of choice or of necessity, which minister 

 to the livelihood of man. No argument is needful to show 

 the bearing of the latter both upon individuals and com- 

 munities. In a manufacturing and commercial country 

 especially, where population is crowded, and where art and 

 labour in their every branch are strained to the utmost reach 

 of human exertion, life becomes subject to influences which 

 act powerfully upon it, and tend on the whole to shorten its 

 duration. The materials and documents we possess are not 

 yet copious and exact enough to justify more certain con- 

 clusions on the subject. That some particular occupations 

 abridge life, by bodily confinement, privation of good air, 

 the direct action of noxious vapours and other causes, is a 

 fact too familiar to all. To this class of causes, acting thus 

 definitely, must be referred in part the difference between 

 town and country longevity; testified in England by the 

 mean annual mortality in the larger towns being twenty-six 

 or twenty-seven in a thousand, while that of the whole king- 

 dom does not exceed seventeen in the same number. The 

 whole subject is one of high interest to our social welfare, 

 and attention is now keenly awakened to it. 



Curiosity may also be directed to the question how the 

 learned professions stand as to relative longevity ? In such 

 an enquiry it is obvious that individual cases go very little 

 way towards its solution. With respect to the profession of 



